Tropospheric and lower stratospheric vertical profiles of ethane and acetylene

The first known vertical distributions of ethane and acetylene which extend into the lower stratosphere are reported. The average upper tropospheric concentrations, between 20,000 ft (6 km) and 35,000 ft (11 km), near 37°N ‐ 123°W were 1.2 µg/m³ (1.0 ppb) for ethane and 0.24 µg/m³ (0.23 ppb) for acetylene while the values near 9°N ‐ 80°W were 0.95 µg/m³ (0.77 ppb) and 0.09 µg/m³ (0.09 ppb), respectively. Detectable quantities of both ethane and acetylene are present in the lower stratosphere. There is a sharp decrease in the levels of these two compounds as one crosses the tropopause and ascends into the lower stratosphere. The observed levels of ethane and acetylene may allow some impact on the background chemistry of the troposphere and stratosphere.